After qualifying in medicine from the University of Oxford, Dr Parfrey completed her training in Respiratory medicine in Cambridge. She was awarded MRC Clinical Training fellowship for structural biology studies on the polymerization of alpha1-antitrysin leading to her PhD at University of Cambridge.

This was followed by a Wellcome Trust Intermediate Fellowship undertaken at National Jewish Health in Denver, Colorado studying the role of TNF signalling in lung injury.  She has clinical and translational research interests in the role of innate immunity and infection in pulmonary fibrosis.  She also has an interest in the genetics of familial and idiopathic pulmonary fibrosis. 

Dr Parfrey is a strong supporter of patient advocacy having established the pulmonary fibrosis patient support group at Royal Papworth Hospital, she was involved with BLF IPF patient charter and is a trustee for the charity Action for Pulmonary Fibrosis.